- The following reference material is based on information updated to Sept. 2007
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Major Products with ECMs:

Series 60 : Detroit Diesel's Series 60 -- start of production in 1987. Detroit Diesel claims that the Series 60 was the first fully integrated heavy-duty diesel engine with electronic controls in the world.

MBE 4000 : Manufactured specifically for North American market, the Mercedes Benz 4000 series engine (MBE 4000) is claimed to be stronger and lighter than any engine in its class.

MBE 900 : In 1998, Detroit Diesel entered the NAFTA medium-duty truck market with the Mercedes Benz 900 engine (MBE 900). The MBE 900 is used in many different medium-duty truck applications including food service, beverage, general delivery, refuse, and towing.

ECM Versions

DDEC I -- Typically found in truck engines manufactured in 1987 -- ECM in cab, no data pages

Features and Concerns

ECMs may be updated in older trucks.

No incident reports are available in a DDEC III unless a Pro-Driver installed. There is calibration data only in a DDEC III (if enabled) which won't be overwritten. Pro-Driver data may be overwritten but contains up to 5 hard brake incidences. The oldest report will be overwritten first.

DDEC IV ECMs produced in October, November, and December 1997 had the clock date set incorrectly. The date is 8 months slow in ECMs built in October and November and 4 months slow in ECMs built in December.

DDEC IV and newer ECMs may contain 3 diagnostic records, 2 hard brake records and one last stop record (defaulted to record but can be set not to record if desired; threshold rate defaulted at 7 mph/sec).

The oldest record will be overwritten first. Last stop records will be overwritten from the moment the vehicle is driven from accident (engine on and vehicle traveling at a speed greater than about 3 mph).

Oldest hard brake may be overwritten if new event occurs after accident while the truck is under its own power.

Fault codes may be lost if ECM is removed from vehicle and read off vehicle without simulating all the sensors. New fault codes may be introduced if a download is conducted on a damaged truck.

An audit trail of who's been in the system will be shown.

Time stamp on all reports relates to ECM clock which drifts up to +/- 3 hours per year.

Features and Concerns

The date, time of record, and snapshot will be logged if the “Quick Stop” rate is set to something other than zero and the threshold is met. The “Quick Stop” feature became available in Nov 1995.

A “Tattletale” showing who’s been making changes in the system will be shown for some engines but not all.

Factory defaults are not preset to record “Quick Stop” data; however, if a fault code is met (such as due to low oil pressure), then a record will be written in Snapshots.

Snapshots can be triggered by the operator by using the Cruise Control Set/Resume Switch or by using Cat ET.

The ECM can store a maximum of 2 snapshots that are triggered by a diagnostic code, 2 snapshots that are triggered manually, and 1 Quick Stop snapshot. The snapshots are stored in a circular buffer. The newest snapshot will replace the oldest snapshot.

If a snapshot record is written due to a critical fault, it will be 9.12 sec pre-threshold, 3.36 sec post-threshold, 0.48 sec increments

Bench downloading without attaching working sensors will create new Snapshots due to “open circuits,” overwriting other Snapshots that exist on the ECM which may have contained useful information.

New snapshot fault codes may be introduced if a download is conducted on a damaged truck with open circuits.

A “0041-04 8 Volt Supply voltage low(21)” snapshot will be logged if the 8 volt supply is less than 7.5 VDC for more than one second and the ECM has been powered for more than 3 seconds.

Battery life: over 5 years

When a two-speed axle is used, the ECM driven speedometer may not work properly during the change of gear ratios from high to low if the ECM is not programmed. The default is “none.”

There are known issues with the time stamp not matching the corresponding data. For example, Quick Stop displays the vehicle speed, brake statues, etc, every second but the actual time between the readings is actually less than 1 second.

2005 was the first year that some ECM’s contained panic stop information. Vehicles older than 2005 must have a Road Relay installed in order to have panic stop information. Road Relay dash mounted display has been an option available since 1993.